The super-sons accompany two scientists with opposing views on the essential nature of man - good or evil - to a newly discovered civilization between South America and Antarctica. But when the experiment doesn't go the way one scientist expects, he interferes in it with deadly results.

Indexer Notes

Batman's wife appears in the story, but her identity is not made clear. Feature bannered as "Superman Junior and Batman Junior" on splash page. The story also has two separate chapter titles: Part 2 - The Human Test Tube; Part 3 - Who the Killer, Who the Prey?